GROUP 1 (SECONDARY STUDY GROUP 1; ONCOTYPE DX RECURRENCE SCORE [ODRS] =< 10): Patients receive standard hormonal therapy (e.g., tamoxifen alone orally (PO), aromatase inhibitor [e.g., anastrozole, letrozole, or exemestane] alone PO, or tamoxifen PO followed by aromatase inhibitor PO) at the discretion of the treating physician for 5 or 10 years.